In The Hub's navigation menu on the left side, you can find an option for the "App Store":

Here you will find applications that have been approved for use in The Hub. There is a toggle in the top-right to switch between the Apps "Desktop" or "Store":

Desktop:
The desktop section will show you all the Apps that you have already downloaded to The Hub.

Store:
The store section is where you can browse available Apps to integrate into The Hub

Note: Agents do not currently have the ability to submit Apps to the App Store

If you have any questions about this or run into any issues, you can contact Technical Support at support@exprealty.net or in exp.world at https://exp.world/techsupport-agent